The Axillary Nerve Block is an intermediate level procedure that will allow you to sharpen your skills as a sonographer since you will be moving your needle around to target three and sometimes four nerve branches (radial, ulnar, median, musculocutaneous). With ultrasound, and with a single point of entry, you will be able to perform this 4:1 block with ease after some practice.

Indications: Upper extremity procedures

External Landmarks: Axilla, axillary crease

Approach: In-Plane our Out-of-Plane

Local Anesthetic Volume: 20 - 30 mls.

Level of Expertise: Intermediate

Anatomy:

The brachial plexus enters the axilla as a squadron around the axillary artery, which will be your main landmark. The nerves are usually located in the following way:

Most Lateral: Median

Most Medial: Ulnar

Beneath the Artery: Radial

View of Axillary Anatomy with a non-linear array ultrasound

Place your arm in anatomical position, and you will see it is easy to remember the above anatomy since your ulnar nerve which innervates your 5th finger (and half of the 4th) will be most medial.

You can do this block in and out of plane. Our preference is in plane since we can usually target all the above nerves, plus the musculocutaneous with a single entry point. This will take some practice, but after a while you will be doing this without much difficulty.